This invention relates generally to a threaded fastener assembly and, more particularly, to a fastener assembly of the type in which a sleeve is adapted to be preassembled with and captivated axially on the shank of a threaded fastener. Even more specifically, the invention relates to a special-use fastener assembly of the type in which the sleeve must be capable of moving axially along the shank through a limited range.
A fastener assembly of this general type is disclosed in Wagner U.S. Pat. No. 4,975,008. In that assembly, radially extending protuberances are formed integrally with the shank of the fastener. The sleeve is formed with a bead which engages the protuberances in order to retain the sleeve axially on the fastener. Because of the protuberances, special techniques are required to form the fastener.
In another type of fastener assembly, a knurl is formed between threaded and unthreaded sections of the shank of the fastener and serves to retain the sleeve axially. The knurl requires the fastener be specially formed and, in addition, the knurl sometimes fails and allows the sleeve to slip off of the end of the fastener.